Ever stumbled upon a situation where a website that has many JavaScript and CSS includes just gives too much errors while being tested with Google’s testing tools? This actually happens and was recently posted in Google’s Webmaster help forums. The website over there had 21 CSS files and 86 JavaScript includes.

Not long after an answer with an explanation came from John Mueller from Google:

The main problem comes down to there just being too many JS (86) & CSS (21) files used in that page. We have to fetch all of them in order to render the page, and since they’re all on the same host (even if one is called “cdn” — it’s the same IP address), we’re limited by the time we have available. With that, we end up dropping some of them, and can’t properly render the page (it doesn’t allow the code to completely run).

So, basically having too much Javascript and CSS includes is just to much to handle by Google’s testing tools and they eventually just give up waiting for a response from the includes. Having said that, you should consider fixing that kind of issue, if you’re having one since this can seriously improve the way your webpage displays to search engines and to your users as well.